If you’ve started up your own company or got tapped to represent your employer at an upcoming business lunch, you may be wondering how many drinks are appropriate to have during the meal. If by drinks you mean water or soda, then chances are you don’t need to worry about it, unless of course you’ve been known to drink several gallons of water when you’re nervous. This might mean that you’re constantly interrupting your lunch to head to the bathroom, which could look a little odd.

Of course, when most people refer to drinks, they’re talking about the alcoholic types that make you feel happy, sad, or angry after you’ve had a few. While there was a time when businessmen made it a habit to toss back several cocktails during lunch―perhaps you’ve watched the show “Mad Men”―nowadays, most people in the business world don’t look kindly on daytime intoxication.

That doesn’t mean, necessarily, that you’ll be forever shunned if you decide to order a beer, wine, or cocktail during a business lunch. Whether you should, and just how many, depends on who you’re meeting with and where.

Business Lunch: How many drinks are appropriate?

Anytime you have a business lunch scheduled, it’s probably a good idea to be, you know, prepared. The reason the word “business” is front of the word “lunch” is because you’re meeting to discuss professional matters. It’s not just an excuse to get out of the office, stuff your face, and talk about last night’s ballgame or the latest movie you watched…although that would be awesome.

In other words, you should have an idea about what matters need to be discussed beforehand, and what kind of business or organization you’re dealing with. Use common sense. If you’re meeting with a 60 year-old executive from a business that produces videos about the “evils of drinking”, then you might want to steer clear of that mid-day Scotch. Or, if they sneer at the server after being told the drink specials and order “just water”, then getting a pint of beer might not go over very well.

That being said, if you’re having lunch with a business partner who makes or distributes wine, then it’s safe to say ordering a glass―particularly one they produce―is fine. In fact, having a glass or two could be good for business. Or, if they quickly order a beer and ask if you mind, it might help seal the deal if you order one yourself. That’s right…it might actually be better if you order a drink.

What’s being discussed?

The agenda for business lunches can vary, and whether you should order a drink can depend on what’s being discussed. If you’re having lunch because your business royally messed up recently, and you’re there to apologize, then tossing back a few drinks might not be the best way to showcase your professionalism.

Or, if you’re discussing urgent and important business matters, then ordering a few shots of whiskey won’t demonstrate that you’re taking the meeting very seriously. You may be accustomed to having a drink or two at lunch periodically, and always end it there, but it’s important to remember they might not know that. In their mind, ordering a drink on any day but Friday is a surefire sign that you’re too casual or you’re looking to get drunk.

Then again, if you’re having a semi-formal lunch with someone you’ve been doing business with for years, then chances are no one’s going to be offended if you order a beer. In fact, offering to buy them a drink could further solidify your relationship.

Where are you eating?

If you’ve been invited to have lunch at the new pub down the street, then you’re probably not going to spoil the meeting by ordering a pint. If you’re having a business lunch at the food court next door, where alcohol isn’t even sold, then you probably shouldn’t crack a beer from the six-pack you picked up earlier.

If you’re having a business lunch at a classy, five-star restaurant, then let the people with whom you’re meeting take the plunge first. If you’re lucky, maybe they’ll suggest ordering a bottle of wine.

How many is too many?

While in the 1970s people may have participated in “three martini lunches” for work (and that’s really what they were called), most etiquette experts today say getting a buzz at a business lunch is far from wise. People nearly always expect their partners or clients to be sober and clearheaded during meetings, so if you’re slurring your speech or cracking inappropriate jokes, then chances are you won’t be doing business with them at anytime in the future.

Of course, if you’re a veteran drinker, then you may be able to down several drinks before you really feel it, but ordering four drinks to their every one probably won’t look good.

A good rule of thumb if you’re participating in an important business meeting is that ordering a drink or two may be completely fine, but you should carefully evaluate your circumstances before ordering any more than that.